


The Warlock, a Demon

by L_ecureuil



Category: Shadowhunters (TV)
Genre: Angst and Hurt/Comfort, Darkfic, Demon!Magnus, Disability, Enemies to Lovers, F/F, F/M, Horror!AU, Human Experimentation, Human Sacrifice, M/M, Murder, PTSD, Psychological Horror, Violence and Blood, Will have a happy ending
Language: English
Status: In-Progress
Published: 2020-01-26
Updated: 2020-01-26
Packaged: 2021-02-27 07:48:59
Rating: Mature
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 2,275
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22423621
Author URL: https://archiveofourown.org/users/L_ecureuil/pseuds/L_ecureuil
Summary: ((The Black Butler AU nobody asked for))Alec has vowed to hunt down the remaining members of the Circle with a demon by his side.
Relationships: Helen Blackthorn/Aline Penhallow, Magnus Bane/Alec Lightwood
Comments: 4
Kudos: 33





	The Warlock, a Demon

_6 years ago..._

Valentine entered the circle of the Circle, his muscles jumping in a medicated fit as he instructed Isabelle’s body to be dragged onto the altar. Alec thrashed, tearing at the cage with the pieces of his nails, his pain meaningless as long as Isabelle was going to die. She’d survived this far, they were some of the few. At first Alec thought they would be lucky because of their parents but after Max had perished in the tank and his parents’ blood had been used up, he knew that being a Lightwood wouldn’t mean some gentler treatment from a madman.

Alec blinked at the blood pouring from his head and rattled the cage again, his voice a hoarse howling against the silence of the procession.

The gabble dropped.

Valentine proclaimed with open arms, “We have gathered here today to sacrifice of a dog of the Clave! So rarely do Nephilim get to use their bodies for a purpose greater than the angels can conjure. And yet here we are. There is a force out there that no man nor angel can even kill with their spears! A god among us, who are already so powerful in our righteous blood! When I sacrifice this child—this once pure beacon now sullied in preparation—I will bring the greatest mystery to its knees before us!”

Alec wished he could bite through the bars, wished he had hands to free her. He wished _she_ could be behind the bars again, just like when she was taken away to be sullied. He wanted to project himself into her bruised form.

Her hair, once fine and soft looking was coarse and fell tangled underneath her. Her eyes were listless as she pounded at her captors. Alec watched her kick like a dying animal.

“Let us offer our prayers! Come Forth!” Valentine took the ceremonial knife in his hand and forced it through Isabelle’s heart to the sound of Alec’s broken scream. “The nefarious beast that sups on spilled blood! Beneath the Protection of the Moon with its thousand faces! Enter into a covenant with me! Come forth, Holy Time, Lord of Anarchy! I summon thee to do our bidding and give us unending immortality in your image!”

“ _You will die for this!_ I’ll kill you! I’ll kill all of you! There is nothing out there and you will _DIE!”_ Alec yelled over them as best he could, trying for a last ounce of fear in them for what they did to him and Isabelle, what all of them did. He felt his world break apart with Isabelle’s ripped body, he felt himself shaking so hard the cage rattled and the candles fell. The crowd gasped in a chorus of religious fervor, but not at Alec, rather at what was materializing in front of him.

**Who Summoned Me Here? Only the truly desperate sacrifice their own blood on an altar while proclaiming there is nothing out there at all.**

“It is I, _Valentine Morgenstern_ ,” Valentine said to the incomprehensible form of eyes and teeth. “The blood of the angels—"

**Not you, it was not you who proclaimed this to enter into your realm. To open this door means I only have eyes for one.**

On queue the thousands of eyes and limbs and things of all means of horror turned their faces on Alec.

Alec mercifully kept his mouth shut, looking into the bottomless void from where the gentle voice arose.

“We are the ones who have summoned you here, it is we who prepared ourselves—” Valentine began but couldn’t speak more as a tendril cut around his neck like cheese-wire, a body of burning darkness forcing its violence into his choking mouth, his head compressed into a torturous hold.

**Be quiet. You did not prepare your body, you were a coward who sat by to watch. You have followed the instructions, yes, the ancients told you, yes, the ghosts were wise, but it was to be you to sully and destroy yourself for me, and you did not. How selfish of you, human. How vain.**

The crowd was picked and thrown, their bodies crashing, and Alec could do nothing but curl into himself and watch with deadened eyes the body of his sister. She was the only corpse that mattered.

**Is this poor wreck my summoner? Someone so desperate they would give their own sister’s soul to a demon.**

Alec looked up at heeled feet, blackened and couldn’t force himself to look further, higher. “I did not sacrifice my sister to you. To anything! _You can’t take her!”_ He rasped against torn vocals, but the demon seemed to understand him still.

**A biting boy, so angry, yet you _did_. What was given cannot be returned, you are, the only true summoner. I would never have come if you hadn’t done this. Your gift is one to make a covenant. I can grant you any wish from this blood guilt. I would become your slave.**

Alec watched the rest of the demon squelch the lives of the Circle members in a bashing fit of heads on marble and heat. He felt so sick, so sick, he couldn’t believe that only two months ago he’d been home and ready to teach Max how to read runes.

“No,” Alec said as firmly as he could in his cracked voice, “I don’t want this, I don’t want you!”

**You may wish me away, and the covenant will be paid.**

So patient for a demon, Alec thought bitterly, it was spitting in his face and laughing at his weakness after it ate his sister. She’d been a genius in life, and an expert in the sciences. Her light had overshadowed him and he loved it, he loved being there for her and even when he didn’t understand her fervor for downworlders and her twisted sense of humour he listened still. Isabelle, Isabelle she’d—she’d—

“I want them to die,” Alec said, “All of them, I want them to suffer for what they did. I want the power to do that. I need to, for her.”

**Will you make a covenant?**

“I—I will make a covenant with you, demon! If that’s what it takes,” Alec whispered, but he knew the demon could hear him, even over the screaming. They were far off and his bubble was all powerful, waiting for the words to be dropped.

**You want my wealth of power to avenge your sister?**

“Yes!” Alec cried.

**And you will make a covenant with me, down the path of hell for your sister’s life?**

“Why do you ask this! I already told you!” Alec hissed through the bars, tears streaming down his face, his body a single brutalized nerve.

**Then you will need a mark, a covenant with me does not leave you unharmed.**

“I want it,” Alec said, “I don’t care about the pain— _Aaarrgh_!” he felt like he’d been shot directly through the head, his body convulsing as he clutched at his eye where blood trickled down his face. Alec had foolishly underestimated the pain again. He’d underestimated how much people wanted to hurt him.

He was so sick of blood, the sticky, grating substance of a smell he couldn’t stand. Having it all over his body like this, being treated as Saint Sebastian tied to the post, bloodied to impossibility. Alec didn’t understand how he was still alive after all this.

He was so sick, so finished with these months of torture he would take anything.

Alec felt his chin being tilted up with sticky tendrils, his eyes shut painfully as he knew he couldn’t fight back.

**How does that feel? With that my power is intrinsically tied to you. Hell is in your hopeless eye and all that comes of it is with you.**

**Tell me, young one, what is your first order with this power of yours?**

Alec looked passed the demon and to Isabelle, then Valentine who was beside her still, whimpering around a claw. He looked up at the demon and made a face, “Kill everyone else in this place, demon. Do it now! I can’t think with them here.”

And the demon did, with such joy Alec had to force himself to look away from the dismemberment. Alec plugged his ears, swallowing down the bile of his empty stomach. 

**Such a sad master, and still so weak. But we will work on that, won’t we?**

Somehow the demon trying to cajole him into comfort was ever worse.

**We have time.**

Alec heard the cage open and cracked a look up at the void.

**A cage is no place for a covenant with me. Come, Shadowhunter. Tell me your name.**

Alec swallowed, “Alexander Lightwood, eldest and head of the Lightwood Family,” he tried to give his title, his name of ancient origins. None of it helped around this demon who could have killed Alec’s ancestors and Alec would never have known.

**Oh, an eldest son? Am I in the presence of Clave royalty? How cute. I suppose I should take on a form which a Clave royal would govern.**

Alec watched in horror as the mass sucked itself into a single human figure. A man so beautiful Alec couldn’t understand why its form couldn’t just be _average_. Maybe the devil did it on purpose, to remind him of the life he could never have. The man’s eyes brightened into golden cat slits and Alec felt like he’d been punched in the gut all over again.

“A _warlock_ ,” Alec said numbly. Isabelle had always talked about how important it was to work with the warlocks, and yet here he was parodying comradeship in a sick mockery. This creature wasn’t a warlock at all.

The charming man spoke, his tasteful suit glimmering with hints of mirthful colour. “Would you rather I become a child, Shadowhunter? Or perhaps a fae?” Alec shook his head. A warlock was just far enough from Isabelle that he could do this. If he was going to use this power to hurt the Circle, he had to be convincing, and warlocks were solitary. No one would ask where a new one came from.

“Alexander Lightwood wants to seek revenge, but he needs parameters. Working with a demon is best when clear cut. A contract must be made,” the demon said, “A Lightwood like you must know all about contracts and business. I saw it in your sister’s memories when I ate her soul,” he truly looked like the cat who got the canary, so soft and sated by the soul he’d eaten. It only drove Alec to greater rage. “You have three wishes.”

Alec looked around at the seeping carnage around him and thought of all the people who hadn’t been able to go to the Academy because of the Circle, all the corruption and promises they’d imbued into the Clave until it was nothing but a rotting core of its former self. His mother always promised they would rise up and be better, but rise up on what? He didn’t know. He saw no future for the Clave until they got rid of all remnants of the Circle, but he didn’t trust the devil to fix things truly, only to trick him like all demons did for pleasure. 

“Never lie to me,” Alec said, “This includes optical illusions and any kind of glamour. You are not allowed to do so.”

The demon titled his head at Alec, looking impressed.

“Of course. It is sealed,” the demon said, “Congratulations.”

“Obey me without question when I say ‘I command you’,” Alec said, “That’s my second wish.”

The demon hummed.

“And the third is protect me from any attack until our contract is over,” Alec said raised his head, bloodied eye still shut and crisp. “You still haven’t given me your parameters. What can you do?”

The demon looked joyously at the chandeliers above him before locking those cat eyes with Alec, “I can’t bring back the dead, but I can do the most incredible things. It’s strange that you’re restricting my power so much.”

“I don’t want an instant fix, that never works,” Alec said, “Change has to come incrementally. I know the world out there better than a demon trapped in a dimension does. Who knows what havoc you’d leave if you went at it alone.” 

The demon leaned in, teeth sharp and grinning, “Now that you’ve given your terms, you should know I am meant to eat your soul. My covenant is mutually beneficial, after all. I will be well fed with you.”

Alec glared, “You already ate my sister’s soul!”

“And you already made a covenant with me without knowing my terms,” the demon seemed so pleased.

“Then, I accept your covenant,” Alec said swiftly.

The demon backed away, gazing at Alec like he was the strange one in this conversation.

“Not surprised by me eating your soul, are you?” the demon said. “I am surprised however that I didn’t notice you’re missing a foot until now.”

“No, I just don’t care about you eating my soul,” Alec said dryly, ignoring his second comment, “After what I’m about to do, I’d rather know I’m damned for certain,” he licked his lips, “Now give me your name, demon.”

“It’s up to you,” the demon said, “I can’t very well go into the world as a warlock with a demon’s name. That’s _too_ obvious.”

“Then, I’ll call you _Magnus Bane_ , because I can already tell that you’re going to be a major pain in the ass.”

“Oof, that hurts,” Magnus said, clutching his heart. "And here I thought we could be friends."

**Author's Note:**

> Next chapter:
> 
> Magnus leaned back on his heels, peering at her under heavy lidded eyes, “If you think Alec ever had feelings for you, you’re a fool,” he said softly, pity in his voice.


End file.
